studio wall concept design? | John Sayers’ Recording Studio Design Forum archive

Hi there "48bondstreet", and welcome! :)

but ive sectioned the walls and ceiling to 600x600 center wood frame modular pieces. each piece would be bolted and glued together.

The concept is interesting, but I doubt that will pass inspection from the structural point of view. Maaaaaybe the walls (but doubtful), but the ceiling certainly won't. For structural integrity, you need solid, single pieces of lumbar that run directly from floor to ceiling with no breaks (in the case of the walls) and that span wall-to-wall unbroken (in the case of the ceiling). Those walls would not be strong at all in sheer either, which is rather important. That ceiling will weight several tons, if built to the level of isolation you are hinting at, so it needs massive structural support. The members would have to be 2x8 or greater, even for a conventional ceiling, considering the spans you are talking about... So I don't think that will fly, structurally. I would run it by a structural engineer, to check, but I think you'll find it doesn't cut it. However, that's not to say you can't build a modular studio in sections that bolt together! You sure can. You just have to do it in sections that make sense structurally: Pieces that run the full height, from floor to ceiling, and pieces that run the fill width of the room, wall to wall.

the joins would be covered with rock wool on the external walls

I don't understand why you want to only cover the joints with mineral wool. In order for the MSM system to work properly and be damped correctly, the entire surface should be covered with absorption, not just the joints. There is no purpose at all to just doing the joints. If the joints are built correctly, then they are no different from the rest of the wall.

i realize this restricts me to a rectangular room

Not necessarily: If designed carefully, there could be angled wall modules and ceiling modules at strategic points.

but with this much unfacesd insulation im expecting it to be seriously dead and i shouldnt have to many issues with room modes or standing waves.

Room modes and standing waves are the exact same thing, just from different points of view. Yes, that much insulation all of the same thickness will make the room sound dead (and unpleasant), so you are correct about that, but not about the modes. There is not enough thickness of insulation to do anything useful for modes. Bass traps need to be very thick (acoustically) and very large to have any real effect on modes. Generally, superchunks are built out to 60 or 80 cm from the corners, and hangers should be at least 50 cm deep, more like 1m if possible (if the room is large enough). You are talking about less than 1/10th of that, so it wont' be making much difference at all. The general recommendation is for at least 10cm thickness of insulation at key points in the room, and perhaps as much as 15cm, in both cases possibly with air gaps behind, plus the bass trapping as needed to deal with room modes. There just isn't enough thickness of insulation in your plan. And since it is all the exact same thickness, you would be treating the exact same group of frequencies in the exact same way, around the entire room, while neglecting all other frequencies.

we only have the luxury of the block walls on 2 sides of our room, the other two will be open to a large steel door (effectively open window) aimed at apartment buildings

How do you plan to deal with that? What will you do to create the outer-leaf in those areas? Without knowing that, it's hard to say what the MSM resonance will be, and therefor hard to guess at what level of isolation you will get. Of course, with no outer leaf you would be limited to mass law, so for the low mass of your proposed walls, you would theoretically get about 33 dB of isolation (roughly the same as a typical house wall, consisting of 2x4 studs with 13mm drywall on each side), so that wouldn't be much use.

is this a viable option for the necessary sound reduction im going to need?

Well, there's the thing: you don't actually say how much you need! :) You say you are "loud" and that you want to be "quiet", but can't plug those into an equation to predict what type of wall you need! You have to have real numbers, in terms of actually measured decibels ("C" weighted, slow response) for both "loud" and "quiet". The difference between those two numbers tells you how much isolation you need. Then it is simply a matter of using the equations, or the published papers with tables of different wall types, to see what types of construction will get you to that number, then comparing that with what you are proposing. The other thing with those small modules is the amount of wood that you would be using: about four times as much as you need, by the looks of it! You are basically doubling up for each stud, and for each cross brace, with twice as many cross braces as are necessary. So that is going to be hugely expensive, in lumber alone, as well as rather slow to build. A good framing team could frame the room you show in a few hours, but they would take days to build it if they had to make dozens of small modules, very accurately, using four times the amount of wood and tne times the number of cuts, then bolt them together, one at a time. The basic concept is a good idea, but the implementation needs adjusting to be workable. - Stuart -